The Atmel JTAGICE mkII supports On-Chip Debugging and programming on all AVR® 8-bit and AVR32 32-bit microcontrollers and processors with On-Chip Debug capability.
Supported interfaces are:
JTAG (AVR32, ATXMEGA, ATmega devices)
PDI (ATXMEGA devices) *Hardware revision 01 only
debugWIRE (ATmega, ATtiny devices)
SPI (ATmega, ATtiny devices)
aWire (AVR32 devices) *Hardware revision 01 only
For more information on which hardware revision your unit is, see Hardware Revisions
Consult the device support section for a full list of devices and interfaces supported by this firmware release.